I recently changed by velocity joints because I was hearing the cracking noise in front when turning when the 4 by 4 was engaged. This solved that problem. Now when 4 by 4 engaged and reversing and turning I heard a loud noise not the same as before. I disengaged the 4 by 4 and no noise. This only happens when reversing and is difficult to reverse without hearing that noise. Any thoughts on what I should check?